Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2014

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Summary of stock based compensation expense

The following table summarizes the Company’s stock-based compensation expense:

In millions	2014			2013			2012
Pre-tax compensation expense	$	34		$	30		$	50
Tax benefit	(12		)	(10		)	(18		)
Total stock-based compensation expense, net of tax	$	22		$	20		$	32

Summary of activity related to non vested equity awards

The following table summarizes activity related to non-vested restricted stock units during 2014:

Shares in millions	Number of Shares		Weighted-Average Grant-Date Fair Value
Unvested, January 1, 2014	1.4		$54.02
Granted	0.3		73.61
Vested	(0.6	)	52.15
Canceled	(0.1	)	57.50
Unvested, December 31, 2014	1.0		60.68

Summary of stock option activity under plan

The following table summarizes stock option activity under the Plan for the year ended December 31, 2014:

In millions except exercise price and contractual terms	Number of Shares		Weighted-Average Exercise Price	Weighted-Average Remaining Contractual Term	Aggregate Intrinsic Value
Under option, January 1, 2014	9.4		$51.95
Granted	0.8		78.71
Exercised	(3.0	)	49.02
Canceled or expired	(0.1	)	60.55
Under option, December 31, 2014	7.1		56.25	5.9 years	$272
Exercisable, December 31, 2014	4.7		51.02	4.9 years	$207

Summary of assumptions used in option models

The Company uses a binomial option pricing model to estimate the fair value of the stock options granted. The following summarizes the assumptions used in the models:

	2014	2013	2012
Risk-free interest rate	0.16-2.83%	0.2-2.9%	0.2-2.1%
Weighted-average volatility	22.9%	21.1%	25.0%
Dividend yield	2.46%	2.72%	2.61%
Expected years until exercise	6.7-7.9	6.6-7.6	7.6-7.8